Portable instrument for electro-optically reading indicia and for projecting a bit-mapped image

ABSTRACT

A portable instrument incorporates an electro-optical assembly for reading indicia during a reading mode, and for projecting a bit-mapped image during a display mode. A manually operable switch on the instrument is disposed for selecting one of the modes. The image is formed by pulsing a laser at selected times on selected scan lines.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.09/604,196, filed Jun. 27, 2000, now U.S. Pat. No. 6,935,566.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a portable instrument forelectro-optically reading indicia, such as a bar code symbol, asignature, or an object image of any object, and for selectivelyprojecting a bit-mapped display image on a viewing surface.

2. Description of the Related Art

Various optical scanning systems and readers have been developedheretofore for reading indicia such as bar code symbols appearing on alabel or on the surface of an article. The bar code symbol itself is apattern of graphic indicia comprised of a series of bars of variouswidths spaced apart from one another to bound spaces of various widths,the bars and spaces having different light reflecting characteristics.The readers function by electro-optically transforming the spatialpattern represented by the graphic indicia into a time-varyingelectrical signal, which is, in turn, decoded into data which representthe information or characters encoded in the indicia that are intendedto be descriptive of the article or some characteristic thereof. Suchdata is typically represented in digital form and utilized as an inputto a data processing system for applications in point-of-saleprocessing, inventory control, distribution, transportation andlogistics, and the like.

A variety of scanning devices is known. The scanner could be a wand typereader, such as shown in U.S. Pat. No. 5,508,504, herein incorporated byreference, including an emitter and a detector fixedly mounted in thewand, in which case the user manually moves the wand across the symbol.As the wand passes over the bar code symbol, the emitter and associatedoptics produce a light spot which impacts on the symbol, and thedetector senses the light reflected back from the light spot passingover each symbol. Alternatively, an optical moving spot scanner scans alight beam, such as a laser beam, across the symbol; and a detectorsenses reflected light from the beam spot scanned across the symbol. Ineach case, the detector produces an analog scan signal representing theencoded information.

Moving spot scanners of this general type have been disclosed forexample, in U.S. Pat. No. 4,387,297; No. 4,409,470; No. 4,760,248; No.4,896,026; No. 5,015,833; No. 5,262,627; No. 5,504,316 and No.5,625,483, all of which have been assigned to the same assignee as theinstant application and each of which is hereby incorporated byreference. As disclosed in some of the above patents, one embodiment ofsuch a scanning system resides, inter alia, in a hand held, portablelaser scanning device supported by a user, which is configured to allowthe user to aim the scanning head of the device, and more particularly,a light beam, at a targeted symbol to be read.

The light source in a laser scanner bar code reader is typically asemiconductor laser. The use of semiconductor devices as the lightsource is especially desirable because of their small size, low cost andlow voltage requirements. The laser beam is optically modified,typically by an optical assembly, to form a beam spot of a certain sizeat the target distance. It is often preferred that the cross section ofthe beam spot measured in the scanning direction at the target distancebe approximately the same as the minimum width in the scanning directionbetween regions of different light reflectivity, i.e., the bars andspaces of the symbol. Although typical readers utilize a single lasersource, other bar code readers have been proposed with two or more lightsources of different characteristics, e.g., different frequencies.

In the laser beam scanning systems known in the art, a single laserlight beam is directed by a lens or other optical components along thelight path toward that includes a bar code symbol on the surface. Themoving-beam scanner operates by repetitively scanning the light beam ina line or series of lines across the symbol by means of motion of ascanning component, such as the light source itself or a mirror disposedin the path of the light beam. The scanning component may either sweepthe beam spot across the symbol and trace a scan line across the patternof the symbol, or scan a field of view of a photodetector, or do both.The laser beam may be moved by optical or opto-mechanical means toproduce a scanning light beam. Such action may be performed by eitherdeflecting the beam (such as by a moving optical element, such as amirror) or moving the light source itself. U.S. Pat. No. 5,486,944describes a scanning module in which a mirror is mounted on a flexelement for reciprocal oscillation by electromagnetic actuation. U.S.Pat. No. 5,144,120 to Krichever, et al., describes laser, optical andsensor components mounted on a drive for repetitive reciprocating motioneither about an axis or in a plane to effect scanning of the laser beam.

Because of the size and optical and electronic complexity of scanningsystems and bar code readers, they generally have heretofore not beencombined with other devices in the same housing. The conventional use ofa liquid crystal display (LCD) on such readers occupies a large viewingarea and limits any proposed reduction in size for a handheld system.

Also known is a laser pointer which is a device that projects a spot oflight on a target, such as a presentation being made by a lecturer to anaudience. The pointer is essentially a flashlight-type device and isusually packaged in a tubular housing.

SUMMARY OF THE INVENTION OBJECTS OF THE INVENTION

Accordingly, it is a general object of this invention to provide animage projector and a bar code reader in the same housing.

More particularly, it is an object of the present invention to provide amanual switch on an instrument to change the instrument between adisplay mode and a reading mode.

It is yet another object of the present invention to provide an imageprojector and a bar code reader in a pen-shaped battery-operated housingthat is able to acquire and store data from bar code symbols, andsubsequently download such data to a computer; the bar code reader maybe operated either as a wand, in which the bar code symbol, located afew inches from the end of the housing, is manually scanned by the user,or as a self-scanning unit using a mirror to scan the laser beam acrossthe bar code symbol.

A still further object of the present invention is to provide a portablecomputer that can optionally be used as an image projector or as a barcode reader.

FEATURES OF THE INVENTION

In keeping with the above objects and others which will become apparenthereafter, one feature of the present invention provides a combinedimage projector and scanner for scanning a target, including a portable,hand-held housing aimable by a user at a target; an electro-opticalassembly supported by the housing, for reading the indicia during areading mode, and for projecting a bit-mapped image on a viewing surfaceduring a display mode; and a mode selector for selecting one of themodes.

In one preferred embodiment, an optical element in the housing ismechanically moved in and out of the path of an emitted laser beamduring the reading mode to focus the laser beam at either a short rangefrom the housing (for bar code reading) or at a substantially greaterrange (for bar code reading). In the reading mode, the housing includesa detector which is activated for detecting at least a portion of lightof variable intensity reflected off the coded indicia and for generatingan electrical signal indicative of the detected light intensity. In thedisplay mode, the movable element is also moved to focus the bit-mappedimage at different distances relative to the housing.

The housing also includes a processor for decoding the electrical signalinto data represented by the coded indicia, a memory for storing thedata within the housing, and a download interface for downloading thestored data to a remote host for further processing.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic view of a prior art hand-held laser scanner anddata collection terminal;

FIG. 1B shows a hand-held pen-type optical reader;

FIG. 2 shows the principal components of a pen-type optical reader;

FIG. 3 demonstrates use of the pen-type optical reader;

FIG. 4A shows an alternative version of the pen-type optical reader;

FIG. 4B shows in more detail the principal components of the pen-typeoptical reader shown in FIG. 4A;

FIG. 5A shows a further alternative pen-type optical reader;

FIG. 5B shows in more detail the principal components of the pen-typeoptical reader of FIG. 5A;

FIG. 5C is a view of the pen-type optical reader of FIG. 5A from adifferent angle;

FIG. 5D is an end view of the reader of FIG. 5B;

FIG. 5E is an opposite end view of the reader of FIG. 5B;

FIG. 6A is a sectional view of an alternative pen-type optical reader;

FIG. 6B is a perspective view of the pen-type optical reader of FIG. 6A;

FIG. 7A shows one method of downloading information from a pen-typeoptical reader according to the present invention;

FIG. 7B shown an alternative method of downloading information from thepen-type optical reader according to the present invention;

FIG. 8 shows a dedicated downloading port from the pen-type opticalreader according to the present invention;

FIG. 9 is a sectional view of the downloading port shown in FIG. 8;

FIG. 10 is a schematic view of a drive for moving the focusing lens;

FIG. 11 is a perspective view of a portable instrument during a displaymode of operation;

FIG. 12 is a block diagram of an electro-optical assembly on theinstrument of FIG. 11;

FIG. 13 is a block diagram depicting the operation of the assembly ofFIG. 12;

FIG. 14 is a diagram of the operation of the assembly of FIG. 12 duringcapture of a signature; and

FIG. 15 is a perspective view of a telephone with a projected displayimage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As used in this specification and in the appended claims, the term“indicia” broadly encompasses not only symbol patterns composed ofalternating bars and spaces of various widths commonly referred to asbar code symbols, but also one or two dimensional graphic patterns, suchas signatures as well as alphanumeric characters. In general, the term“indicia” may apply to any type of pattern or information which may berecognized or identified by scanning a light beam and/or a field of viewof a photodetector, and detecting reflected or scattered light as arepresentation of variations in light reflectivity at various points ofthe pattern or information. A bar code symbol is one example of an“indicia” which the present invention can scan.

FIG. 1A illustrates an example of a prior art bar code symbol reader 10implemented as a gun shaped device, having a pistol-grip type of handle53. A lightweight plastic housing 55 contains a light source 46, adetector 58, optics 57, signal processing circuitry 63, a programmedmicroprocessor 40, and a power source or battery 62. Alight-transmissive window 56 at the front end of the housing 55 allowsan outgoing light beam 51 to exit and an incoming reflected light 52 toenter. A user aims the reader 10 at a bar code symbol 70 from a positionin which the reader 10 is spaced from the symbol, i.e., not touching thesymbol or moving across the symbol.

As further depicted in FIG. 1A, the optics may include a suitable lens57 (or multiple lens system) to focus the scanned beam into a scanningspot at an appropriate reference plane. The light source 46, such as asemiconductor laser diode, introduces a light beam into an optical axisof the lens 57, and the beam passes through a partially-silvered mirror47 and other lenses or beam shaping structures as needed. The beam isreflected from an oscillating mirror 59 which is coupled to a scanningdrive motor 60 energized when a trigger 54 is manually pulled. Theoscillation of the mirror 59 causes the outgoing beam 51 to scan backand forth in a desired pattern.

A variety of mirror and motor configurations can be used to move thebeam in a desired scanning pattern. For example, U.S. Pat. No. 4,251,798discloses a rotating polygon having a planar mirror at each side, eachmirror tracing a scan line across the symbol. U.S. Pat. No. 4,387,297and No. 4,409,470 both employ a planar mirror which is repetitively andreciprocally driven in alternate circumferential directions about adrive shaft on which the mirror is mounted. U.S. Pat. No. 4,816,660discloses a multi-mirror construction composed of a generally concavemirror portion and a generally planar mirror portion.

The multi-mirror construction is repetitively reciprocally driven inalternate circumferential directions about a drive shaft on which themulti-mirror construction is mounted.

The light 52 reflected back by the symbol 70 passes back through thewindow 56 for transmission to the detector 58. In the exemplary reader10 shown in FIG. 1A, the reflected light reflects off of mirror 59 andpartially-silvered mirror 47 and impinges on the light sensitivedetector 58. The detector 58 produces an analog signal proportional tothe intensity of the reflected light 52.

The signal processing circuitry includes a digitizer 63 mounted on aprinted circuit board 61. The digitizer processes the analog signal fromdetector 58 to produce a pulse signal where the widths and spacingsbetween the pulses correspond to the widths of the bars and the spacingsbetween the bars. The digitizer serves as an edge detector or waveshaper circuit, and a threshold value set by the digitizer determineswhat points of the analog signal represent bar edges. The pulse signalfrom the digitizer 63 is applied to a decoder, typically incorporated inthe programmed microprocessor 40 which will also have associated programmemory and random access data memory. The microprocessor decoder 40first determines the pulse widths and spacings of the signal from thedigitizer. The decoder then analyzes the widths and spacings to find anddecode a legitimate bar code message. This includes analysis torecognize legitimate characters and sequences, as defined by theappropriate code standard. This may also include an initial recognitionof the particular standard to which the scanned symbol conforms. Thisrecognition of the standard is typically referred to asautodiscrimination.

To scan the symbol 70, the user aims the bar code reader 10 and operatesmovable trigger switch 54 to activate the light source 46, the scanningmotor 60 and the signal processing circuitry. If the scanning light beam51 is visible, the operator can see a scan pattern on the surface onwhich the symbol appears and adjust aiming of the reader 10 accordingly.If the light beam 51 produced by the source 46 is marginally visible, anaiming light may be included. The aiming light, if needed, produces avisible light spot which may be fixed, or scanned just like the laserbeam 51. The user employs this visible light to aim the reader at thesymbol before pulling the trigger.

The reader 10 may also function as a portable data collection terminal.If so, the reader 10 would include a keyboard 48 and a display 49, suchas described in the previously noted U.S. Pat. No. 4,409,470.

In view of the relative simplicity, availability and adaptability ofinformation systems including bar code symbol data storage capability,it is desirable to develop systems particularly suitable for consumerapplications. An optical reader which has many consumer applications isshown in FIG. 1B. The arrangement, generally designated as 80, comprisesa pen-shaped main body 81 having at its writing end an optical scannerelement light emitter and detector 82 for reading a bar code symbolillustrated schematically as 83. The pen may also include actual writingcapability, for example by having the writing nib adjacent the opticalelement 82 or, indeed, having the writing element and the opticalelement 82 at opposing ends. It is desired to increase the range ofapplications for such a product. The data processing capabilities ofsuch a system 80 are limited by its physical size and power supplypotential consequently limiting the range of applications of thearrangement. In addition various problems arise in actual operation ofsuch a system, in particular in regulating the varying speeds at whichconsumers scan given bar code symbol 83.

An embodiment of an optical reader to be used in conjunction with thepresent invention is shown in FIG. 2. Although a pen-type optical readeris shown, it will be appreciated that any other hand-held configurationwould be appropriate for use in conjunction with the present invention.Although specific constructional details are also discussed in moredetail below, it will be appreciated that data storage/processingelements and optical reader elements of known type can replace thespecific components discussed in a manner that would be well known tothe skilled person. A discussion of pen-type readers is found in U.S.Pat. No. 5,506,392, commonly assigned herewith and incorporated hereinby reference.

The pen-type optical reader (henceforth referred to as a “pen reader”)is generally referenced 90 in FIG. 2. It will be appreciated that theexact shape of the pen reader as illustrated may be exaggerated, forexample in width, in order to show more clearly each of the principalcomponents and how they interact. In the embodiment shown, the penreader 90 comprises a ballpoint pen 91, 92 together with the opticalreader 93 itself. The pen reader need not actually have writingcapability, or may be in the form of any suitable writing implement suchas a pencil, a fountain pen, a marker pen and so forth. Indeed theoptical reader sub-system discussed in more detail below can be in amodular form insertable into a suitably configured writing implementhousing of any desired type.

The writing element of the pen reader 90 is shown schematically as aball-point pen cartridge 91 together with a projection/retractionmechanism generally designated 92 and of any suitable known type.Evidently it is desirable to reduce the size of those elements 91, 92 asfar as possible to allow maximum space for the reader module.

The reader module is generally designated 93. The components andconstruction of the module 93 will be generally well known to theskilled person and are described only briefly hereafter for the purposesof completeness. The reader module 93 includes a light source 94, forexample, a laser or LED and a reflector 95. A reading beam generated bythe light source 94, is reflected by the reflector 95 out of a readingwindow 96. The reading beam is reflected by a bar code symbol generallydesignated as 97, passes once more through the reading window 96 and isreceived by a detector 98. The reader module 93 may be a field of viewreader in which case the mirror 95 is a fixed mirror and the detector 98comprises a CCD (charge coupled device) array, or a scanning system inwhich case reflector 95 is driven by a motor schematically shown at 99for scanning motion. The light source 94, detector 95 and, ifappropriate, motor 99 are connected to a processor, control and datastorage element 100 in conjunction with a power source 101. Theprocessor element 100 controls operation of the various components andalso acts as a data storage and processing device for bar codeinformation read by the module 93. As discussed in more detail below, itis desired to download the information stored in processor element 100at a later stage to an external device. Accordingly a data output portis provided and is fed by line 102, preferably adjacent to or inconjunction with the reading window 96.

A particular implementation proposed according to the present inventionfor the pen reader 90 occurs in relation to consumer information access.For example where a consumer carries a pen reader 90 and is reading aprinted publication including advertisements, the text of theadvertisements may not contain sufficient information concerning theproduct advertised, nor, of course can the advertisements act as anymore than encouragement for the consumer to purchase the product shouldthe consumer subsequently encounter the product, introducing the riskthat the consumer may forget about the product.

Where, as in FIG. 3, the advertisement carries a bar code symbol 122,however, many of these problems can be rectified for a consumer 120carrying a pen reader 90 of the type shown in FIG. 2. When anadvertisement for example in a magazine 121 is of interest to theconsumer 120, the consumer simply scans the corresponding bar codesymbol 122 with the reader pen 90. The bar code information is stored inthe processing element 100 and, to the extent desired, processed. Inparticular, information contained in the bar code symbol 122 relating tothe advertised product is stored. As a result the consumer has anautomatic reminder of the product he wishes to purchase as well asinformation relating to the product. Evidently, where the consumer 120sees more than one product of interest, the relevant information canalso be stored, the storage capabilities of the reader pen 90 beinglimited only by the storage space in the processor element 100.

A particular implementation of the present invention allows the consumerto subsequently download the information stored in the reader pen 90 ina manner described in more detail below. In particular the informationcan be downloaded to a personal computer or other access point to acomputer or data network. The downloaded information can then be used invarious different manners. For example the product can be ordered oradditional information concerning the product can be accessed. Aparticular implementation proposed under the present invention is thatthe bar code symbol accompanying the advertisement contains sufficientinformation for the personal computer or access point to the computernetwork to access a site on the Internet (or comparable data storagesystem). This site can contain additional information concerning theadvertised product, information concerning related products, priceinformation, cross-references to further related sites, and thecapability of ordering and paying for the product. This greatlysimplifies the purchasing process and also ensures that the consumerdoes not forget a product which has caught his attention.

In addition, further information can be derived according to the presentinvention. For example the impact of the advertisement and popularity ofthe product can be assessed for future marketing purposes, andquantifying the amount of printing space that should be assigned to theadvertisement based on its popularity. Preferably the reader pen 90 hasa dedicated user and carries user identification information such as acredit card number, or other identification carried under an approvedsystem. As a result, during purchase of the product, details of thetransaction can be based on that information. In addition a customerprofile can be built up based on the consumer's buying patterns.

It will be seen that the system can be extended to other applications.For example where an abstract of text is printed together with a barcode symbol, the bar code symbol can contain information which, whendownloaded, can provide access to additional or related text.

Assuming high enough resolution, the bar code symbol can even be readoff a VDU or other visual display system in a closed system in order toaccess additional information on the Internet.

Where the bar code symbol is for use in conjunction with the Internet orparallel system, the information contained in the bar code symboleffectively comprises an Internet address. When that information isdownloaded to a personal computer, the personal computer communicateswith a dedicated server which captures the Internet address and useridentification information and re-routes to the advertiser's web sitefor information retrieval and delivery to the consumer's personalcomputer. Accordingly, the downloaded information would enable theconsumer to go directly to a relevant home page or a relevant sub-page.A resolution server on the system could be used to collect informationfrom all users, not only for information purposes but also for billingand routing purposes.

Various alternative pen reader configurations are shown in FIGS. 4 to 6.Referring firstly to FIGS. 4A and 4B, a reader pen 130 includes a penassembly 132 including a ball pen cartridge, for example, of the typesold under the trade mark Zebra F-refill and an actuating mechanism 134of a known type rotatable to extend and retract the ball pen cartridge.The pen reader 130 further includes a trigger 136 manually actuable toenable a scan together with a cooperating internal switch 138 example,code ITT KSC 421. The reader pen 130 includes a wand tip 140 for readinga bar code symbol. A data output port is also provided at 137. Thesystem is powered by a battery 142 of any suitable compact type. Alsoincluded is a beeper 144 or other audible device which can sound toindicate to the user that a bar code symbol has been successfully read,that the battery power is low, that there is little memory space leftand so forth. Different audible tones or sequences of audible tones canrepresent different warning signals. In addition the pen reader 130 caninclude a screen (not shown) carrying information as to the status ofthe pen reader and any instructions for use thereof.

FIGS. 5A to 5E show a slight variant in which, where appropriate, thesame reference numerals have been used as for FIG. 4. It will be seenthat the exit window for the reader (here shown as a laser scanner at131) is in an inclined face relative to the longitudinal axis of thereader pen 130, allowing improved ergonomics in reading a bar codesymbol. The reader further includes a grip 133, for example made ofleather, around a portion of its length allowing improved user grip andcomfort.

FIGS. 6A and 6B show a further alternative configuration schematicallyonce again using the same reference numerals where appropriate as inFIGS. 4 and 5.

Various methods of downloading the information are contemplated. Twoapproaches are shown in FIGS. 7A and 7B. In a preferred configurationshown in FIG. 7A, a personal computer is shown at 150 being of theportable type although a fixed type computer will also, of course,suffice. The personal computer 150 includes a keyboard 152 and a screen154 and can generally be of conventional type. The personal computer 150includes a data input port 156 arranged to communicate with the penreader data output port 103. In the embodiment shown, the output port103 of the pen reader 90 is touched against the data input port 156 onthe personal computer 150. Touching the input port 156 firstly commencesthe downloading sequence and secondly allows accurate and rapidcommunication between the pen reader 90 and the personal computer 150.The interface between the pen reader data output port 103 and the datainput port 156 can, for example, be of the “memory button” or “touchmemory” type, for example, as sold by Dallas Semiconductors. The actualinterface is of well known type and, in effect, the information storedin the pen reader 90 is communicated to the port 103 provided at anappropriate point on the pen reader 90. The information is converted toa suitable form for transmission at the port 103 and, on contact withthe data input port 156 of the personal computer 150, the transmissionis activated. The data input port 156 is configured to receive andconvert into a suitable form information transferred from the port 103.In particular the information can be transferred in the form of a seriesof electronic pulses representing bits. Such a system gives rise to asimple and substantially error-free interface allowing a user todownload information stored in a reader pen 90 to a personal computer150 quickly and accurately.

As will be appreciated, various other downloading methods arecontemplated within the ambit of the present invention. For example asshown in FIG. 7B, a fixed-type personal computer 160 including akeyboard 162, a display screen 163 and a mouse 164 includes a microphone166 which receives an audio signal from a corresponding speaker dataoutput 168 on a reader pen 90. A button (not shown) or other switch canbe included on the reader pen 90 to activate transmission by the speaker168. The information stored in the reader pen 90 is converted to a highfrequency audio signal at the speaker 168 which is received by themicrophone 166 and decoded. Of course, the transmitter can transmitother forms of radiation, for example, it can be an optical or microwavetransmitter with a suitable receiver being provided on the personalcomputer.

Yet a further downloading system is shown in FIG. 8. A dedicated datadownloading port 170 includes an orifice 172 for receiving a reader pen90. The port 170 communicates information downloaded from the pen reader90 via a line 174. Referring to the sectional view shown in FIG. 9, itwill be seen that the port 170 includes a data receiving interface 174of any of the types described above which communicates with the readerpen 90 for downloading of information. Downloading can be contactactivated by contact between the pen reader 90 and the interface 174, oractivated by pushing a button or other switch (not shown) on the penreader. The interface 174 communicates with a processor 176 forconverting the downloaded information, if necessary, into a formatappropriate for a computer network, and the information is communicatedto the computer network via line 173.

It will be seen that all of these methods comprise a user-friendlysystem for downloading scanned information from a pen reader. Use of aport of the type shown in FIGS. 8 and 9 is particularly suitable whereit is not desired to rely on the consumer having a computer or otherhome access to a suitable computer network. The port can, for example,be provided at a retail outlet or other point of sale. It should benoted that the pen reader can also be writable via the data port,personal computer or other means (even a bar code symbol itself) toinput user information of the type discussed above. This wouldfacilitate short term usage of a pen reader allowing a given user toinput information temporarily for the duration of his or her use of thepen reader.

The range of applications of the system as a whole is evidently verywide. For example, a consumer could use the pen reader while on anairplane or in other areas where access to the Internet was notimmediately available. In addition to advertisements and editorial textof the type described above, the system could be used to store andaccess information concerning items in many other applications, forexample in warehouse storage systems.

It will be seen that the above teachings relate to any scanner typesuitable for hand-held scanning and being essentially portable, capableof reading a bar code symbol or similar information carrying symbol. Theinformation can be downloaded from memory in the hand-held scanner bymeans of any suitable interface to a personal computer or other accesspoint or computer network, and corresponding information called up froman Internet web site or corresponding main memory location.

Although the invention has been discussed with reference to certainhousings, triggering or mode-switching mechanisms and other features ofthe disclosed embodiments, it will be understood that a variety ofhousing styles and shapes and triggering mechanisms could be used. Otherconventional features of bar code reading systems can also be includedif so desired. The invention is preferably implemented usingminiaturized components such as those described herein or in thematerials referenced herein, or otherwise known in the art.

Additionally, even though the present invention has been described withrespect to reading one dimensional bar codes, it is not limited to suchembodiments, but may also be applicable to more complex indicia scanningor data acquisition applications such as two dimensional bar codes andmatrix array symbols comprised of geometric shapes. It is conceivablethat the present invention may also find application for use withvarious machine vision or optical character recognition applications inwhich information is derived from indicia such as printed characters orsymbols, or from the surface or configurational characteristics of thearticle being scanned.

In addition to being packaged in specific housings, the elements of thescanner may be implemented in a very compact assembly or OEM subassemblysuch as a single integral module or “scan engine”. Such a module caninterchangeably be used as the dedicated pointer/scanning element for avariety of different writing instruments, housings, operating modalitiesand types of data acquisition systems.

The module could advantageously comprise various optic subassembliesmounted on a support, and photodetection components, such as aphotodiode, charge coupled or solid state imaging device. Control ordata lines associated with such components may be connected to anelectrical connector mounted to enable the module to be electricallyconnected to a mating connector associated with other elements of thedata acquisitions system.

An individual module may have specific scanning or decodingcharacteristics associated with it, e.g., operability at a certainworking distance, or operability with one or more specific symbologiesor printing densities. The characteristics may also be defined throughthe manual setting or factory setting of control parameters associatedwith the module. The user may also adapt the data acquisition system toscan different types of articles or operate at different ranges, or thesystem may be adapted for different applications by interchangingmodules in the data acquisition system through the use of a simpleelectrical connector.

The scanning module described above may also be implemented within aself-contained data acquisition unit or portable computer including oneor more such components as keyboard, display, printer, data storage,application software, and databases. Such a unit may also include acommunications interface to permit the data acquisition unit tocommunicate with a host computer, or other components of a dataprocessing system, or with remote computers through a local or wide areanetwork or with the telephone exchange network, either through a modem,XDSL interface or an ISDN interface, or by low power radio broadcastfrom a portable terminal to a stationary or mobile receiver andthereafter to other system components.

Although we refer to the optical reader 90 as a “pen reader” forconvenience, it is to be understood that the reader may be operableeither as a fixed beam “wand” type reader, in which the symbol isscanned by manual motion of the reader by the user to move the beam spotacross the symbol, or a moving beam scanner in the reader itself inwhich a motor drive moves a mirror (or other optical element orassembly, including possibly the light emitter) to create a moving beam.The optical reader of the present invention may also be embodied indifferent housings other than “pen” shaped housings.

Another embodiment of the present invention provides the capability ofoptionally utilizing the pen reader 90 as a light pointer, using thebeam emitted from the light source 94 (which for reasons of visibilitywould typically be a semiconductor laser). Such laser pointers areuseful for highlighting features in a slide presentation, allowing thelecturer to stand at some distance away from the screen. In such anapplication of the pen reader, the reflector 95 may or may not beactivated, depending on whether one wanted a stationary spot pointer, ora pointer which projected the image of a line or circle on the target.The description of the operation of a convertible pointer/bar codereader (in a housing without the writing instrument) is described ingreater detail in U.S. patent application Ser. No. 08/936,288, which ishereby incorporated by reference.

A manually operated multi-position trigger switch (such as the clip C,in FIG. 2 or a slide switch as shown in the embodiment of FIG. 4) may beused to switch between the various modes of operation of the pen reader.In a first position of the switch, the laser diode 94 is switched off,and no beam is produced. In a second position, the laser diode isswitched on and is reflected from the stationary mirror 95, therebyproviding a fixed pointing beam. In a third position of the switch, thescanning mirror 95 is actuated, causing the beam to be scanned, therebygenerating a visible line on the surface that is being pointed to. Inthe preferred embodiment, the scanning is in one dimension so that theresultant line on the screen is straight. In an alternative embodiment,however, the scanning mirror 95 could cause the beam to be scanned intwo orthogonal directions, thereby forming any desired pattern, such asa Lissajous pattern or a circle, on the screen. More complex scanningarrangements could also be envisaged, with the laser being turned on oroff at predetermined intervals in conjunction with a predetermined scanpath in a plane being implemented so that a predetermined image orcurvilinear figure can be projected onto the screen such as a square ortriangle, or a pattern of dots forming any other desired figure.

One of the differences between operating in a bar code reading mode anda pointing mode is that the target is located at, and the beam spot isfocused at, a distance of a few inches in a reading mode, and at ten ortwenty feet in a pointing mode. The laser diode itself will normally bepackaged with a focusing lens that focuses the beam spot for bar codereading at a relatively short predetermined working range from the endof the reader. In order to implement a dual distance, and dual modedevice, an additional lens L1 may be provided which is disposed withinthe housing and moved into the optical axis of the first focusing lenswhen the pointing mode is activated. Thus, in the pointing mode, thebeam will pass through two lenses and will focus at a substantialdistance away from the end of the pointer. Lenses L1 may be mechanicallymoved in and out of the beam path by direct action of the switch beingmanually moved by the user between reading and pointing modes ofoperation.

For example, pushing the clip C in an inward direction may move the lensL1 along a track and click into a predetermined fixed position in thepath of the outgoing laser beam. The track can be spring loaded, so thatanother movement of the clip C will release it out of the beam path.

Alternatively, lenses L1 may be fixed in position in the housing, andthe beam path moved into either L1 or a clear path to the window. Inthat alternative, the beam path may be moved by the mirror, or bychanging the position of the source.

If the trigger is a multi-position trigger, the positions of the triggercould be programmed so that different contacts correspond to differentprojected images. Thus, the pen could provide an image of a straightline when the trigger is set in a first position and a projected circlewhen the trigger is set in another position. Different positions of thetrigger could also provide different lengths of line and/or differentsizes of circle or other images that are being projected.

Scanning of the beam, of course, reduces the visibility of the imagewith respect to the visibility of the spot generated by a fixed beam. Tocompensate, the laser output power may be increased depending upon theposition of the trigger or the mode of use.

The convertible laser pointer/scanner of this embodiment may also beembodied in a stylus for a pen computer, such as shown in U.S. Pat. No.5,369,262, herein incorporated by reference. Such stylus can be usedwith active matrix or passive (pressure sensitive) display terminals.The laser pointer may also be embodied in a writing instrument, such asa pen or mechanical pencil, such as depicted in U.S. patent applicationSer. No. 08/794,782, herein incorporated by reference.

In addition to the above noted features, it is possible to incorporateother features into the pen, including making it a miniature portablecomputer with a small (e.g., 1-line) LCD display, and a small number ofinput buttons for entry of data or control operations, or a trackballfor scrolling. A voice recorder can also be implemented for takingdictation or reminder messages. A radio receiver may also beincorporated with the same housing so the unit may function as a pagerwith a small, one-line display.

Voice recognition or motion detection may be used to initiate operationof any predetermined computer function. To the extent a moresophisticated motion detection system could be implemented in the pen,handwriting recognition, signature verification or authorization, andsimilar functions could be implemented. The motion of the pen in spacecould also be captured in memory and translated into equivalent text sothat the pen does not have to actually write on paper in order for thedata “written” by the motion of the pen to be recorded.

Alternatively, the laser pointer may also be embodied within the housingof a portable, hand-held data terminal or computer (sometimes called a“portable digital assistant”) such as depicted in U.S. patentapplication Ser. No. 09/047,015.

Rather than switching between a pointing and a reading mode, themanually operated multi-position trigger switch may be used during thereading mode to move one of the components, for example, the lens L1,between a first position in which the light beam is focused at a firstfocus within a first working distance relative to the window 96, and asecond position in which the light beam is focused at a second focuswithin a second working distance relative to the window 96. One of thefoci may be located inside the housing, or at the window, or at aclose-in distance near the window in order to read close-in indicialocated in the first working distance at a range of several inches awayfrom the window. The other of the foci may be located at a far-outdistance away from the window in order to read far-out indicia locatedin the second working distance at a range of several feet away from thewindow.

Thus, the instrument can read close-in and far-out indicia by moving themovable component which, as previously mentioned, can be jointly movedby sliding a button on a slide switch mounted on the housing, or can bemoved by a drive that is electrically energized by manually pressing abutton on a switch.

FIG. 10 schematically depicts a push button switch 200 which, whendepressed, causes an electromagnetic coil 202 to generate anelectromagnetic field that interacts with a permanent magnetic field ofa permanent magnet 204. The focusing lens L1 is mounted for jointmovement with the magnet 204. The magnet is cantilever mounted on aflexure 206, such as a leaf spring, having its end opposite the magnetanchored and fixed in position. The interaction of the fields causes theflexure 206 to oscillate and, in turn, moves the lens in and out of theoptical path, thereby focusing the light beam traveling along thisoptical path to be focused at the first or the second focus toselectively read indicia located at one of the foci.

In accordance with this invention, rather than incorporating a writingimplement in the portable housing, the electro-optical assembly in theinstrument includes not only a bar code scanner as described above, butalso an image projector for projecting a bit-mapped image, such as analphabetic word 210 depicted in FIG. 11. The projector may include itsown subassembly of components separate from the scanner components, butpreferably, at least some of the components are shared and are selectedto perform its function by a mode selector switch 212 mounted forsliding movement on a pen-shaped housing 214 for movement between a pairof switched states corresponding to a pair of reading and display modes,respectively.

As more specifically depicted in FIG. 12, a light source such as a laser216 energized by a drive 218 emits a laser beam to a first x-mirror 220oscillatable by an x-drive 222 for horizontally moving the laser beamback and forth at a first sweep frequency f_(h) along a first direction,commonly termed “X-axis” sweeping, and, in turn, to a second y-mirror224 oscillatable by a y-drive 224 for vertically moving the laser beamup and down at a second sweep frequency f_(v) along a second direction,commonly termed “Y-axis” sweeping. The first and second directions aremutually orthogonal. The first or horizontal sweep frequency isgenerally much faster than the second or vertical sweep frequency. Inthe preferred embodiment, f_(v)=60 Hz and f_(h)=3.8 kHz. A controlprocessor 228 is operative for controlling a time synchronizinggenerator 230 which, in turn, controls the x-drive 222 and the y-drive226 to insure that the x-mirror 220 and the y-mirror 224 oscillate atthe correct speeds. An x-scanner feedback circuit 232 and a y-scannerfeedback circuit 234 monitor the sweep frequencies of the mirrors 220,224 and assist the drives 222, 226 in maintaining the rated speeds. Acrystal oscillator 238 serves as the master clock.

The resulting light pattern known as a “raster” is identified in FIG. 11by the reference numeral 240. Starting at point A, a spot of focusedlight from the laser 216 is swept by the drive 222 at the horizontalfrequency along the X-direction to the point B to form a first scanline. Thereupon, the drive 226 sweeps the spot from the point B at thevertical frequency along the Y-direction to form a second scan line. Theformation of successive scan lines proceeds in the same manner. In apreferred embodiment, for a display area or a projection screen 236measuring on the order of 4 square inches (e.g., 2.25 inches×1.75inches) at a distance of about 15 inches from the instrument, theresolution of the raster is about 120 lines or pixels along the height(Y-direction) and about 64 pixels along the width (X-direction).

The image 210 is created in the raster pattern 240 by pulsing the laser216 on and off at selected times under the control of the processor 228and the generator 230 which, in turn, control the laser drive 218. Thelaser 216 produces visible light and is turned on only when a pixel inthe desired image is desired to be seen. For example, the letter “L” inthe image word “SYMBOL” in FIG. 11 is formed by turning the laser on atpixel D in a scan line, and again at pixel E in another scan line, andso on until the vertical leg of the letter “L” is formed. The horizontalleg of the letter “L” is formed by turning the laser on at successivepixels F, G, H, along the same scan line.

Every letter or number can be formed by this technique. Indeed, anyimage, including graphical designs and logos, and even bar code symbols,can be formed from a plurality of such bits arranged along the X-andY-axes. Fonts can be stored in a font file in memory 242 for access bythe processor 228.

Returning to FIG. 12, the same laser 216 can be used in the reading modefor reading symbols, and in the display mode for projecting the beamspots. The mirror 220 is shared in both modes, and the mirror 224 isshared only when two axis reading is desired. The manual selection bythe switch 212 is depicted in FIG. 12 by the user input box 244.

The assembly can fit in a volume of about 12 mm in diameter by about 12mm in length and, hence, can fit in a housing configured as a pen, aring, a key chain, a pendant, or any other device having a small formfactor. As mentioned above, the liquid crystal display (LCD) is acomponent that limits size reduction in many devices. An LCD has auseful viewing angle limited to about 30 degrees and typicallyartificial light is required to provide adequate brightness to read thedisplay. Hence, the LCD is not useful in highly miniaturizedapplications with which this application is concerned and, as a result,the image 210 need not be projected at a distance from the housing 214as depicted in FIG. 11, but can be projected onto the projection screen236 located on and built into an exterior wall of the housing itself,or, as will be explained below in connection with FIG. 15, can belocated on a nearby surface adjacent the housing and, in someapplications, can even be projected onto the user's palm which serves asa convenient projection screen.

The image area is roughly 4 to 8 square inches to achieve a contrastratio of around 4:1 to enable easy viewing. A larger image area wouldrequire the laser power to exceed CDRH-II safety levels if the displaybrightness and contrast ratio are to be maintained. Conversely, thebrightness and contrast ratio are reduced for an increased display areaif the laser power is kept constant.

The display area can be changed dynamically by changing the scan anglesof the mirrors 220, 224, or by varying the operating power or the scanspeed. The image height is scanned at a minimum of 40 Hz to reduceflicker. The x-mirror 220 is preferably a flat mirror mounted on atorsional band. The center of rotation of the mirror is symmetrical tothe rotating axis to minimize audible noise.

The laser power is preferably varied with the scan speed to maintain adisplay of uniform visibility. The product of laser power and pixelduration should remain a constant throughout the display. The on-offduration of each spot during a scan line can be varied so that the lineresolution can be considered infinite.

A mask can be included in the housing to block the scan lines at the topand bottom of the raster pattern 240 to reduce distortion due to scanspeed variation. The mode selector need not be a slide switch 212, butcan be any user actuated switch or button, and even voice activation canbe used.

As described so far, the instrument has a reading mode in which it canread one- or two-dimensional symbols, and a display mode in which it canproject a bit-mapped image on a screen or analogous viewing surface. Ifthe symbol is a URL address, the instrument can be made Web capable toprovide Internet browsing via a wireless link. Information from awebsite can be downloaded into the instrument and displayed by the imageprojector.

The instrument can be used in reverse as a camera or capture device tocapture an object image, such as the word “SYMBOL” 260 in FIG. 13, or tocapture a handwritten signature 262 in FIG. 14, in a capture mode. Thefield of view can be changed dynamically by varying the scan angles ofthe mirrors 220, 224. The resolution can be varied by dynamicallychanging the scan speed. The image 260 in FIG. 13 can be captured by ascan board 264 on which the electro-optical assembly is mounted togenerate a DBP waveform file which, in turn, is conducted to a waveformgenerator 266 and the image projector 268 to generate the display. Toreduce noise during signal capture, the laser light during eachhorizontal scan line can be pulsed to sample the image.

In the case of a pen-shaped instrument, accelerometers can be integratedtherein, for sensing the motion of the pen as the user writes. Theaccelerometers also sense hand-jitter and correct the hand-jitter. Bysensing the movement of the user's hand, the signals from theaccelerometers can be used to dynamically change the size of the displayor to zoom-in on a particular area of the display. For example, movingthe pen terminal closer to the projection screen will enable a zoom-indisplay.

The accelerometers can also sense the movement of the hand and pan thedisplay. Hence, it can be used as a scroll bar. For example, moving thepen sideways will pan the display left and right, and moving the pen upand down will scroll the display up and down. Of course, the display canbe scrolled or panned by voice, trackball or “touchscreen” input.

The laser projection display of this invention is superior to aconvention LCD display because the projection display has a view angleof ±90°, only consumes power on demand, and can generate an image largerthan the instrument itself. As shown in FIG. 15 for the application of acellular telephone 270, the projection display 272 can be projected onthe exterior surface of a cover 274 used to overlie and protect thekeypad 276 when the phone is not in use.

In other applications, the miniature size of the electro-opticalassembly can be mounted on the side of a user's head, for example, in aneyeglass frame, for projecting an image on an eyeglass lens in theuser's field of vision.

It will be understood that each of the elements described above, or twoor more together, also may find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in aportable instrument for electro-optically reading indicia and forprojecting a bit-mapped image, it is not intended to be limited to thedetails shown, since various modifications and structural changes may bemade without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

1. A handheld, electronic device for displaying a bit-mappedtwo-dimensional image, comprising: a) a housing having an opaque displaypanel connected to the housing; b) an energizable laser in the housingfor projecting a laser beam toward the display panel when energized; c)a scanner in the housing for sweeping the laser beam along a pluralityof light paths over the display panel; and d) a controller in thehousing operatively connected to, and operative for energizing, thelaser at selected positions of the laser beam in at least one of thelight paths to generate individual light pixels at the selectedpositions on the display panel, and at a refresh rate at which thepixels persist to enable a human eye to steadily view the imagecomprised of a light pattern of the pixels on the display panel, thedisplay panel being electrically unenergized during display of theimage.
 2. The device of claim 1, wherein the device is a telephone, andwherein the display panel is a cover hinged to the telephone.
 3. Thedevice of claim 2, wherein the telephone has a keypad, and wherein thecover is movable between a stored position in which the cover overliesthe keypad, and a display position in which the image is projected onthe display panel.